Automatic target recognition and management system

ABSTRACT

An apparatus for controlling weeds, which includes a tine formation adapted to remove or disrupt targeted weeds, and a tine support assembly adapted to support the tine for movement about a first control axis in a generally vertical direction between an engaged position wherein the tine formation in use contacts a ground surface for removal or disruption of targeted weeds and a disengaged position wherein the tine formation is substantially retracted from the ground surface. The tine support assembly is further adapted to support the tine for movement about a second control axis in a generally horizontal direction. The tine support assembly further includes a first actuation mechanism adapted to effect movement of the tine about the first control axis, and a second actuation mechanism adapted to effect movement of the tine about the second control axis. The apparatus also includes a sensing system for sensing aspects of an environment and generating data indicative thereof, and a classification system for identifying target weeds within the environment on the basis of the data from the sensing system. A control system is adapted to activate the first and second actuation mechanisms of the tine support assembly in accordance with a predetermined control logic thereby sequentially to position the tine for disruptive contact with the targeted weeds.

FIELD OF THE INVENTION

The present invention relates generally to an automated apparatus,method and system for managing weeds or similar pests in the context ofagriculture, plant cultivation or environmental management.

The invention has been developed primarily for targeting and mechanicalremoval of weeds and will be described predominantly in this context. Itshould be appreciated, however, that the invention is not limited tothis field of use, being potentially also adaptable for feeding orwatering plants, harvesting produce, pollinating plants, trimming,pruning or thinning foliage, or other analogous purposes wherein thetargeting and end-effector positioning systems may be effectivelyutilised. The invention is also potentially adaptable for identifyingand controlling pests and diseases, in particular being potentiallyadaptable for detecting, controlling and/or removing foreign bodies froma site or predetermined region such as, for example, sticks, bones,mice, spiders, rats, insects, rubbish and other waste.

BACKGROUND OF THE INVENTION

The following discussion of the prior art is intended to place theinvention in an appropriate technical context and enable its advantagesto be more fully appreciated. However, any references to prior artthroughout this specification should not be construed as an express orimplied admission that such art is widely known or is common generalknowledge in the relevant field.

It is well known that one of the most important aspects in agricultureand crop cultivation is the effective management of weeds. Weeds competeaggressively for limited resources in terms of space, water, sunlightand nutrients. Consequently, the emergence of weeds has a marked adverseimpact on crop yield and quality. Moreover, due to their relatively fastgrowth rates compared to crops, if weeds are not eliminated oreffectively managed, particularly during the early stages after cropplanting, they can quickly dominate entire fields and result in seriousyield losses.

In an attempt to ameliorate this problem, various chemical herbicideshave been developed. However, a number of associated problems andlimitations have emerged including the cost of these agriculturalchemicals and associated application equipment, short and longer-termenvironmental toxicity effects, human toxicity effects including in somecases carcinogenic effects, increased herbicide resistance andincompatibility with organic farming techniques.

In an attempt to avoid these problems, a variety of mechanical weedingdevices and systems have been developed, which can be broadlycategorised as: —

-   -   manual weeding implements and tools such as hoes;    -   mechanical weeding implements adapted for towing behind tractors        or similar vehicles and utilising tines, hoes, brushes or blades        to kill, remove or disrupt weeds; and    -   robotic systems using automated or semi-automated manipulators        to remove or disrupt targeted weeds.

Robotic systems offer potential benefits in terms of automation andhence reduced labour cost. However, to date such systems have been proneto significant disadvantages or shortcomings including one or more of:an inability to accurately and consistently discriminate between weedsand crops or other plants; lack of precise control over manipulators; aninability to trace complex trajectories and operate effectively outsidehighly ordered or structured environments; an inability to accuratelytarget weeds in close proximity to crops or other obstacles; aninability to integrate effectively with a variety of vehicular or otheroperating platforms; excessive size; excessive power consumption; poorreliability; and/or excessive cost.

It is an object of the present invention to overcome or ameliorate oneor more disadvantages of the prior art, or at least to provide a usefulalternative.

SUMMARY OF THE INVENTION

Accordingly, in a first aspect, the invention provides an apparatus forcontrolling weeds, the apparatus including:

a tine formation adapted to remove or disrupt targeted weeds;

a tine support assembly adapted to support the tine formation formovement about a first control axis in a generally vertical directionbetween an engaged position wherein the tine formation in use contacts aground surface for removal or disruption of targeted weeds and adisengaged position wherein the tine formation is substantiallyretracted from the ground surface, the tine support assembly beingfurther adapted to support the tine formation for movement about asecond control axis in a generally horizontal direction;

the tine support assembly further including a first actuation mechanismadapted to effect movement of the tine formation about the first controlaxis, and a second actuation mechanism adapted to effect movement of thetine formation about the second control axis;

a sensing system for sensing aspects of an environment and generatingdata indicative thereof;

a classification system for identifying target weeds within theenvironment on the basis of the data from the sensing system; and

a control system adapted to activate the first and second actuationmechanisms of the tine support assembly in accordance with apredetermined control logic thereby to position the tine formation fordisruptive contact with the targeted weeds.

The term “disruptive contact” as used herein is intended to beinterpreted broadly from a functional perspective, encompassing anydegree of direct contact sufficient to kill, remove, damage, disturb,disrupt or dislodge a targeted weed, as well as close proximity withoutdirect contact but sufficient indirectly to kill, remove, damage,disturb, disrupt or dislodge the foliage, root system or soilsurrounding the targeted weed so as to impede further growth orpropagation.

In one embodiment, the tine support assembly includes a resilient biasmechanism adapted in the engaged position to urge the tine downwardlyinto contact with the ground surface with a bias force, whereby the tineis able to penetrate the ground surface to a degree sufficient toeffectively remove or disrupt the targeted weeds, while allowing adegree of retraction of the tine against the bias force, while in theengaged position, to automatically accommodate obstacles such as rocks,soil clumps, irrigation lines or other obstacles.

In one embodiment, the resilient bias mechanism takes the form of one ormore mechanical springs. In other embodiments, the resilient biasmechanism takes the form of elastic straps or bands. In yet otherembodiments, pneumatic or electromagnetic spring mechanisms may be used.The spring mechanism may be fixed, statically adjustable or dynamicallyadjustable, for example to accommodate different degrees of soilhardness or compaction, different varieties of weeds or crops, differentconfigurations of tines, and other relevant factors. Additionally, theactuation mechanism may be operated so as to emulate a dynamic spring,for example by operating the controller in torque mode, whereby torquecan be sensed through changes in current, hydraulic pressure, pneumaticpressure, or by means of torque sensors. Complementary damping elementsmay also be incorporated into the spring mechanism and again theseelements may be fixed, statically adjustable or dynamically adjustable.In some embodiments, the apparatus includes a spring mechanism operablein relation to the first control axis, to return the tine to thedisengaged or a home position, thereby reducing energy consumption andproviding a safe, convenient and deterministic fail state.

Preferably, the second actuation mechanism is operable to effectmovement of the tine in a generally horizontal direction with the tinein the engaged position in contact with the ground, in a mannerreminiscent of a seismograph tracer, whereby the tine controllablytraces a path responsive to the control system, in order to target weedswithin the operational envelope. In some embodiments, the tine isdesigned and structured for relatively high lateral stiffness tofacilitate accurate lateral positioning, in conjunction with relativelylow vertical stiffness to provide passive spring or resilientdeformation characteristics in the vertical direction.

In one embodiment, the first actuation mechanism includes an hydraulic,pneumatic or electro-mechanical actuator adapted to move the tinegenerally vertically about the first control axis between the engagedand disengaged positions. In one relatively straightforward form, asimple two-position actuator is used. In other more sophisticatedembodiments, progressive actuators or electric servo motors may be usedin order to provide progressive, proportional or incremental control ofthe tine between the engaged and disengaged positions.

Similarly, the second actuation mechanism may include an hydraulic,pneumatic or electro-mechanical actuator adapted to move the tinelaterally about the second control axis between predetermined outerlimit positions. In one relatively straightforward form, this may alsobe a simple two-position actuator. In other more sophisticatedembodiments, progressive actuators or electric servo motors arepreferably used in order to provide progressive, proportional orincremental control of the tine between the limits of lateral excursion.

In one embodiment, the tine incorporates or supports a fluid conduit,which may be adapted to convey a liquid pesticide, herbicide, fertiliseror other agricultural chemical or additive in the form of a jet, steam,drip feed or spray, to the targeted weeds, or alternatively to targetedcrops. In a variation of this embodiment, the fluid conduit may beadapted to convey a jet or spray of liquid such as water to facilitateremoval, dislodgement or disruption of the targeted weeds. In one form,for example, a water jet regulated by the control system in conjunctionwith the tine may be used to physically sever the stems of the targetedweeds. It will be appreciated that this functionality may also be usedunder alternative targeting and control logic as a means ofsystematically irrigating, pruning, trimming, thinning, edging orharvesting plants or crops. In further embodiments, the fluid conduitmay also be used in conjunction with the tine as a seed-feeding andplanting mechanism. The fluid conduit may also be used to convey fineparticulates or powders in a stream of carrier liquid or gas, such asair, for a variety of purposes including artificial pollination.

In a second aspect, the invention provides an apparatus for controllingweeds, the apparatus including:

a plurality of tine formations disposed in a generally transverse lineararray, each tine formation being operable in use to remove or disrupttargeted weeds;

a tine support assembly adapted to support each of the tine formationsfor movement about a first control axis in a generally verticaldirection, whereby each tine formation in the array is independentlymovable in use between an engaged position wherein the respective tineformation contacts a ground surface for removal or disruption oftargeted weeds and a disengaged position wherein the tine formation issubstantially retracted from the ground surface, the tine supportassembly further including a plurality of first actuation mechanisms,each adapted to effect movement of a respective one of the tineformations about the first control axis;

a sensing system for sensing aspects of an environment and generatingdata indicative thereof;

a classification system for identifying target weeds within theenvironment on the basis of the data from the sensing system; and

a control system adapted independently to activate the first actuationmechanisms of the tine support assembly in accordance with apredetermined control logic thereby to position the respective tineformations for disruptive contact with the targeted weeds.

In this form of the invention, it will be appreciated that thehorizontal control dimension provided by the second control axis andassociated actuation mechanism of the first aspect of the invention, iseffectively provided by selection and actuation of the appropriate tine,or combination of tines, within the linear array. It should beappreciated that the rotational control axes of the tines in thisembodiment need not be collinear, but may alternatively be offset,staggered or arranged in other configurations. Such alternativearrangements may diminish the likelihood of clashes between adjacenttines and/or reduce the likelihood of rocks or other debris becomingentangled in or between the tines.

In one embodiment, the apparatus is adapted to be propelled or drawn bya prime mover such as a tractor, harvester, utility vehicle, truck, quador the like. In such cases, the apparatus may be fixed to or integratedwith the prime mover, or towed behind, for example in a trailer or otherancillary powered or unpowered vehicle.

In one embodiment, the apparatus is attached to, towed or pushed by, orintegrated with, an unmanned ground vehicle (UGV), for example of thetype adapted to traverse successive rows of crops. In one preferredform, an omni-directional, self-propelled, autonomous UGV is utilised.Control of the UGV may be partly or fully automated as part of anoverall environmental scanning, route planning, and targeting controlmethodology, optionally operating systematically in conjunction with aplurality of like or complementary autonomous vehicles.

In some embodiments, the tine support assembly includes additionaldegrees of freedom, to provide more flexibility for positioning andorienting the tine. For example, in one embodiment the tine supportassembly of the targeting mechanism may be adapted for movement aroundadditional rotational control axes, and/or along translational controlaxes. In some embodiments, the tine is telescopically extensible.

In one embodiment, the tine and support assembly constitute the endeffector of a multi-DoF (multiple degrees of freedom) robotic arm, withthe robotic arm providing at least one kinematic degree of freedom ateach of a plurality of revolute joints, connected by intermediate links.In some embodiments, the robotic arm itself may comprise the tinesupport assembly and the associated targeting mechanism.

In some embodiments, the sensing system includes a camera adapted togenerate a 2-D image of the environment, and the control system includesa mathematical transformation algorithm to correlate the pixel space ofthe image from the camera to the positions of the actuators in the tinesupport assembly. More sophisticated embodiments utilise 3-D imaging andmulti-modal sensing for mapping and localisation. Examples of sensorsthat may be used for mapping and localisation include infrared,ultraviolet, visual, laser ranging or Lidar, hyperspectral, inertial,acoustic and radar-based sensing systems.

In one embodiment, the apparatus includes a second sensing system forsensing in real time the position and orientation of the tine, as partof a feedback control loop. This enables the possibility of collisiondetection with non-targets, determining success rate for targets,detecting anomalies such as inadvertent deposition of dirt or debrisonto non-targets, and other potentially useful control inputs. In otherembodiments, however, it will be appreciated that parameters related tothe position and orientation of the tine may alternatively be determinedor calculated by means of an open loop control strategy, optionallyutilising respective pre-defined intermediate reference or waypoints forthe actuators regulating the position or orientation of the tine. Insome embodiments, at least one sensor of the sensing system may bemounted directly on the tine, to facilitate targeting.

Preferably, the control system includes a prioritisation algorithm forprioritisation of targets for the apparatus. In one embodiment, thealgorithm is based on a relatively simple “first-in-first-out” (FIFO)prioritisation strategy. In other embodiments, however, additionaloptimisation parameters may be incorporated into the control strategy,including vehicle velocity, time or distance required for the tine toreach each target, related consequences (e.g. inadvertently hitting aneighbouring plant rather than a targeted weed in close proximity),opportunity value parameters such as the relative size of differenttarget weeds, or the like.

The control system preferably also includes a strategy for globalregistration, whereby global coordinates of each target are estimatedusing one or more sensors. In some embodiments, this strategy records acentre position for each target that has been hit, and verifies that anysubsequently identified target is beyond a predetermined minimumdistance, (for example, an error or exclusion zone defined within anerror circle, ellipse or other geometrical boundary) from targets thathave previously been hit, with potential targets within those zonesbeing disregarded in favour of the next target. In some embodiments, thedimensions of these error or exclusion zones are fixed, or adjustable,around the recorded or calculated centre position for each target.

In some embodiments, the control algorithm includes a methodology fordynamically determining, assigning and storing for each target a uniqueerror or exclusion zone, based on real-time data relating to specificinputs such as errors in imaging, real time kinematic (RTK) data,ranging data, and the like.

In more sophisticated embodiments, the state information of the featuresin the environment are incorporated into a world map, which includesdimensions such as mapping, localisation, feature classification (weeds,crops etc), feature states (such as what has been hit), errorestimation, exclusion zones and/or memory of previous world maps orparts thereof.

In some embodiments, multiple robots or autonomous UGVs are networkedand configured to communicate with a central control system, which isadapted to store state information and generate higher level plans.Another variation utilises a decentralised system, wherein multiplerobots can communicate and coordinate directly between themselves,thereby obviating the need for a central control system.

In a third aspect, the invention provides an apparatus for controllingweeds, the apparatus including:

a tine formation adapted to remove or disrupt targeted weeds;

a tine support assembly adapted to support the tine formation formovement about at least one control axis in a predetermined directionbetween an engaged position wherein the tine formation in use contacts aground surface for removal or disruption of targeted weeds and adisengaged position wherein the tine formation is substantiallyretracted from the ground surface;

the tine support assembly further including at least one actuationmechanism adapted to effect movement of the tine formation about thecontrol axis;

a sensing system for sensing aspects of an environment and generatingdata indicative thereof;

a classification system for identifying target weeds within theenvironment on the basis of the data from the sensing system; and

a control system adapted to activate the actuation mechanisms of thetine support assembly in accordance with a predetermined control logicthereby sequentially to position the tine formation for disruptivecontact with the targeted weeds.

In a further aspect, the invention provides an apparatus for controllingweeds, the apparatus including:

a weeding implement for disrupting a targeted weed or pest;

a vacuum system having a suction device (e.g. nozzle) arranged adjacentto the weeding implement;

a support assembly adapted to support the weeding implement and suctiondevice for movement about at least one control axis in a predetermineddirection between an engaged position wherein the weeding implement inuse contacts a ground surface for disruption of the targeted weed orpest and a disengaged position wherein the weeding implement issubstantially retracted from the ground surface;

the support assembly further including at least one actuation mechanismadapted to effect movement of the weeding implement and suction deviceabout the control axis;

a sensing system for sensing aspects of an environment and generatingdata indicative thereof;

a classification system for identifying target weeds or pests within theenvironment on the basis of the data from the sensing system; and

a control system adapted to activate the actuation mechanism of thesupport assembly in accordance with a predetermined control logicthereby sequentially to position the weeding implement for disruptivecontact with the targeted weeds or pests, and the suction device forsubsequent removal of the disrupted weeds or pests.

In some embodiments, the actuation mechanism is adapted for controllingmovement of the weeding implement and suction device with reference to acartesian, SCARA, parallel, polar, or other coordinate reference system.

It will be appreciated that such arrangements incorporating a vacuumsystem for removing disrupted weeds or pests can, in certainembodiments, offer advantages in terms of minimising undesirable seedspreading, thereby potentially reducing weed occurrence rates over timeas the seeds and weeds themselves are completely removed from croppingsoil.

In further aspects, the invention provides automated methods and systemsfor identifying, targeting and removing or disrupting weeds, using theapparatus as described.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way ofexample only, with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of an autonomous agricultural weedingapparatus incorporated into an omni-directional unmanned ground vehicle(UGV) with the tine formation in the engaged position, in accordancewith a first embodiment of the invention;

FIG. 2 is an enlarged perspective view showing the weeding tine and tinesupport assembly of the apparatus of FIG. 1 in more detail;

FIG. 3 is an enlarged perspective view similar to FIG. 2, showing analternative embodiment of the weeding tine and tine support assembly foruse with the apparatus of FIG. 1;

FIG. 4 is an enlarged perspective view, showing a further embodiment ofthe tine support assembly providing a third control axis, for use withthe apparatus of FIG. 1;

FIG. 5 is a perspective view of an autonomous agricultural weedingapparatus, incorporating a series of tines supported for independentactuation in a linear array, in accordance with a second form or aspectof the invention;

FIG. 6 is an enlarged perspective view showing one of the tines andassociated tine support assemblies of the apparatus of FIG. 5;

FIG. 7 is an enlarged perspective view similar to FIG. 6, showingalternative embodiments of the tine and tine support assembly, for usewith the apparatus of FIG. 5;

FIG. 8 is a flowchart showing a diagrammatic representation of ahigh-level control methodology for a weeding apparatus and system inaccordance with one embodiment of the invention;

FIG. 9 is a flowchart showing a diagrammatic representation of controllogic for locating targets and engaging the tines (without registration)as part of an overall control strategy;

FIG. 10 is a flowchart showing a diagrammatic representation of controllogic for locating targets, incorporating registration with a targetmemory in global coordinates;

FIG. 11 is a flowchart showing a diagrammatic representation of controllogic for locating targets and moving tines to target areas (withoutregistration) as part of an overall control strategy;

FIG. 12 is a flowchart showing a diagrammatic representation of controllogic for locating and killing target weeds, incorporating registrationwith a target memory in global coordinates;

FIG. 13 is a flowchart showing a diagrammatic representation of controllogic for killing or disrupting weeds, based on a side-to-sidetrajectory of the tines, as part of an overall control strategy usingthe apparatus and system according to one embodiment of the invention;

FIG. 14 is a perspective view showing an alternative embodiment of thetine and tine support assembly, incorporating a multi-prong end effectorweeding implement coaxially coupled to a hose of a vacuum system, andleading to a mulching device;

FIG. 15 is a perspective view of an autonomous agricultural weedingapparatus incorporated into an omni-directional unmanned ground vehicle(UGV) with the multi-prong implement and vacuum system of FIG. 14;

FIG. 16 shows the omni-directional unmanned ground vehicle (UGV) of FIG.15 travelling above a crop bed, targeting weeds for removal;

FIG. 17 is a perspective view showing an alternative embodiment of thetine and tine support assembly in which a multi-prong end effector ismounted to a multi-DOF robotic arm, and a vacuum hose is positionedadjacent to the multi-prong end effector and leads to a mulching device.

PREFERRED EMBODIMENTS OF THE INVENTION

Referring initially to FIGS. 1 and 2, the invention provides anautonomous weeding apparatus 1. The apparatus includes a tine formation2 adapted to remove, dislodge or disrupt targeted weeds 3 as the tine isdrawn along a planted row or seed bed 4.

A tine support assembly 10 is adapted to support the tine 2 for movementin a generally vertical direction about a horizontally oriented firstcontrol axis 12. In this way, the tine is movable in use between adownwardly oriented engaged position (as shown in FIG. 1) wherein thetine contacts or penetrates the ground surface for removal or disruptionof the targeted weeds, and an upwardly oriented disengaged positionwherein the tine is substantially retracted from the ground surface. Thetine support assembly 10 is further adapted to support the tine formovement in a generally horizontal direction about a vertically orientedsecond control axis 14. In this embodiment, the tine support assemblytakes the form of a turret providing orthogonal pan and tilt controlaxes for the tine. In other embodiments, however, it will be appreciatedthat these degrees of freedom may be oriented differently or provided inother ways, for example by translational movement or telescopicextension, optionally in conjunction with one or more rotational controlaxes.

The tine support assembly 10 further includes a first actuationmechanism 20 (housed within the turret but concealed from view in FIGS.1 and 2) adapted to effect movement of the tine about the first controlaxis 12 and a second actuation mechanism 22 (also housed within theturret but concealed from view in FIGS. 1 and 2) adapted to effectmovement of the tine about the second control axis 14.

In this embodiment, the first actuation mechanism takes the form of afirst electric servomotor disposed within the body of the supportassembly and adapted to rotate the tine about the first control axisbetween the engaged and disengaged positions. Similarly, the secondactuation mechanism takes the form of a second electric servomotor alsodisposed within the body of the support assembly or turret and adaptedto rotate the tine about the second substantially vertical control axis14. It should be appreciated, however, that in other embodiments, theactuation mechanisms may alternatively include hydraulic, pneumatic,electro-mechanical or other suitable forms of actuation. These actuationmechanisms may involve relatively simple two-position actuation control,or in more sophisticated embodiments, proportional or incremental 2-axiscontrol of the tine within its operational envelope.

FIG. 3 shows an alternative embodiment of the tine and support assembly,for use in the apparatus of FIG. 1. In this case, it will be seen thatthe first actuation mechanism takes the form of a first electric rotaryservomotor 24 adapted to effect rotation of the tine about the firsthorizontally oriented control axis 12, thereby to effect movement of thetine in the vertical direction between the engaged and disengagedpositions. The second actuation mechanism takes the form of a secondelectric rotary servomotor 25 adapted to effect rotation of the tineabout the second vertically oriented control axis 14, thereby to effectside-to-side movement of the tine in the horizontal direction while inthe engaged position in contact with the ground. The movement of thetine in this control dimension is reminiscent of a seismograph tracer,whereby the tine controllably traces a path responsive to the controlsystem, to facilitate disruptive contact with targeted weeds within theoperational envelope, as described more fully below.

FIG. 4 shows a further embodiment of the tine support assembly. In thiscase, it will be seen that the 2-axis turret of the support assembly ismounted on a carriage 26, which is slideably engageable withcomplementary guide rails 27. The carriage is thereby supported for alimited degree of linear excursion along a fore-aft axis, in response tomovement of linear actuator 28. This arrangement provides a thirdcontrol axis enabling forwards and backwards motion of the 2-axis tinesupport assembly. The additional control axis may be utilised to inducea higher relative velocity when the tine is targeting weeds and also, byenabling a degree of “backtracking”, to reduce the number of missedweeds. This in turn may enable a higher constant vehicle speed and/or ahigher weed kill rate in particular applications.

The apparatus further includes a sensing system 30 for sensing aspectsof the environment and generating data indicative thereof. In someembodiments, the sensing system includes a camera adapted to generate a2-D image of the environment, and the control system includes amathematical transformation algorithm to correlate the pixel space ofthe image from the camera to the positions of the actuators in the tinesupport assembly. More sophisticated embodiments utilise 3-D imaging andmulti-modal sensing for mapping and localisation. Examples of sensorsthat may be used for mapping and localisation include infrared,ultraviolet, visual, laser ranging or Lidar, hyperspectral, inertial,acoustic and radar-based sensing systems.

A classification system is provided to identify target weeds, andoptionally also non-targets such as plants or crops, within theenvironment, on the basis of the data from the sensing system andappropriate classification criteria.

A control system 35 is adapted to activate the first and secondactuation mechanisms of the tine support assembly 10, in accordance withpredetermined control logic, thereby sequentially to position the tineso as to kill or at least disruptively contact the targeted weeds. Thereference to predetermined control logic is intended to include adaptivealgorithms and machine learning strategies that evolve or refine overtime.

The tine or tine support assembly further includes a resilient biasmechanism adapted in the engaged position to resiliently urge the tinedownwardly into operative contact with the ground surface, with apositive bias force. In this way, the tine is able to penetrate theground surface to a degree sufficient to effectively kill, remove ordisrupt the targeted weeds, while allowing retraction of the tineagainst the bias force to automatically accommodate obstacles such asrocks, soil clumps, irrigation lines or other obstacles. The resilientbias mechanism thereby acts as a form of suspension for the tine,maintaining optimal functional contact between the tine and thecultivated soil in the engaged position, with sufficient compliance toaccommodate obstacles and undulations in the surface terrain.

In one embodiment, the resilient bias mechanism takes the form of one ormore mechanical springs, positioned to urge the tip of the tinedownwardly so as to penetrate the ground surface in the engagedposition. In other embodiments, the resilient bias mechanism may takethe form of elastic straps or bands. Further variations includepneumatic or electromagnetic spring mechanisms. In one form, the tineitself is formed from a material incorporating a degree of elasticity orresiliency, such as spring steel, whereby the resilient bias mechanismis inherent in the shape, configuration and material composition of thetine itself.

In various embodiments, the spring mechanism may be fixed, staticallyadjustable or dynamically adjustable to accommodate different degrees ofsoil hardness or compaction, different varieties of weeds or crops,different configurations of tine, and other relevant factors.Complementary damping elements (not shown) may also be incorporated intothe resilient bias mechanism, and again in terms of dampingcharacteristics, these elements may be fixed, statically adjustable ordynamically adjustable.

In some embodiments (not shown) the tine incorporates or supports asupplementary fluid conduit, which may be adapted to convey a liquidpesticide, herbicide, fertilizer or other agricultural chemical oradditive to the targeted weeds, or alternatively to targeted crops. Forexample, in one variation of this embodiment, the tip of the tine may beused to mechanically dislodge weeds, while the fluid conduit associatedwith the same tine may be used with similarly precise targeting to addchemical fertilizer, irrigation water or other supportive agriculturalchemicals to plants or crops under cultivation. In another variation,multiple fluid conduits may be integrated with or supported by the tine,for example one conduit to direct an herbicide toward targeted weeds,and another conduit to direct a fertiliser toward targeted plants.

In a further variation of this embodiment, the fluid conduit may beadapted to convey a jet of liquid such was water to facilitate removal,dislodgement or disruption of the targeted weeds. In one form, forexample, a water jet regulated by the control system in conjunction withthe tine may be used to physically sever the stems of targeted weed. Itwill be appreciated that this functionality may also be used underalternative targeting and control logic as a means of systematicallyirrigating, pruning, trimming, thinning, edging or harvesting plants orcrops. In further embodiments, the fluid conduit may also be used inconjunction with the tine as a seed-feeding and planting mechanism.

The apparatus may be propelled by any suitable form of prime mover, andmay also be mounted to a stationary platform. In the embodiment shown,the apparatus is attached directly to, or integrated with, an unmannedground vehicle (UGV) 50. The UGV of the preferred embodiment is acompact, omni-directional vehicle incorporating a chassis 52, and fourindependently driven and independently steerable wheels 54 inconjunction with electric drive motors, batteries, optionally solarpanels to extend battery life, as well as on-board sensors, controlmodules, memory and data storage modules, navigational equipmentincluding GPS, receivers, transmitters and ancillary equipment asrequired. It will be appreciated that this vehicular platform providesfurther degrees of freedom to facilitate positioning and orientation ofthe tine, based on the positioning of the omni-directional platform ofthe UGV itself. If required for particular applications or to extend theoperational envelope, the tine may also be mounted to the UGV platformby means of an intermediate robotic arm. In some embodiments, the tinemay also be telescopically extensible in order to provide an additionaldegree of freedom of movement and extended operational range.

It should be understood that a wide variety of other ground-basedvehicles are also envisaged for use in conjunction with the apparatus,with different numbers of wheels, tracks, legs or skids includingrail-mounted carriages and a range of options for motive power,steering, navigation and the like. This extends to multi-leggedautonomous walking vehicles or robots and unmanned aerial vehicles(UAVs). Moreover, it should be understood that multiple tines andassociated support assemblies may be mounted to a single vehicularplatform for substantially simultaneous coordinated operation, therebyproviding redundancy, increased efficiency, extended operational rangeand potentially higher vehicle speed. Various embodiments of the systemmay also be retro-fitted to existing agricultural equipment or vehiclesincluding tractors, trailers, ploughs, harvesters, quads, or the like.

In other embodiments (not shown), the apparatus may be attached to afixed base station, optionally in conjunction with a plurality of likebase stations disposed in spaced apart relationship, with adjoining oroverlapping target zones, and operating in concert to provide effectivecoverage of a defined target area to be weeded.

A further form of the invention is shown in FIGS. 5 to 7, whereinsimilar features are denoted by corresponding reference numerals. Thisform is also integrated into an omni-directional UGV 50. In this case,however, it will be seen that a plurality of tine formations 2 aredisposed in a generally transverse linear array 60, each tine beingoperable in use to remove or disrupt targeted weeds. In this case, thetine support assembly is adapted to support the tines for movement in agenerally vertical direction about the first control axis. Thus, eachtine in the array is independently movable in use between the engagedposition for removal or disruption of targeted weeds as the tine isdrawn along the ground by the UGV, and a disengaged position wherein thetine is substantially retracted to a position above the ground surface.Although not shown in the interests of clarity, it will be understoodthat the apparatus may incorporate additional covers, housings, guardsor shrouds as appropriate to provide adequate protection for the tines,support assemblies, actuators and associated componentry. The system mayalso include a user interface whereby an operator may interact directlywith the system by means of a computer, mobile electronic device (wiredor wireless) or remote control station.

FIG. 6 shows a first variation of the tine and associated supportassembly 10 for this embodiment. In this case, the actuator (not shown)is mounted externally to the supporting body 61.

FIG. 7 shows a second variation of the tine and support assembly forthis form of the invention, in which it will be seen that the linearactuator 62 is mounted substantially within the supporting body 61 toeffect rotational movement of the tine about the horizontally orientedfirst control axis 12, and thereby to effect generally vertical movementof the remote end of the tine between the engaged and disengagedpositions.

In this form of the invention, the discreet tine support assemblies 10which are interconnected to form composite tine support assembly 66,include a plurality of the first actuation mechanisms 62, for examplehydraulic or pneumatic actuators, or electric servomotors, each adaptedto effect movement of a respective one of the tines about itscorresponding first control axis. In this embodiment, the first controlaxes 12 of the tines are substantially coaxial but it should beappreciated that this need not necessarily be the case. For example, thetines may be staggered, alternately offset, or arranged in othersuitable configurations.

It will also be noted that in this form of the invention, the individualtines are not supported for lateral or horizontal movement based onrotation about a second control axis. Rather, as best seen in FIG. 5,the horizontal control dimension is effectively provided by selectionand actuation of the appropriate tine, or combinations or clusters oftines within the linear array, based on the control strategy. Ifrequired, a tine self-cleaning control mode may be implemented, wherebythe tines clean themselves by way of relative movement or rapidshuffling between adjacent tines to dislodge earth, rocks or otherdebris.

In some embodiments, the system incorporates a conveyer system (e.g.belts, buckets, rollers) or other transfer means (e.g. vacuum,peristaltic pumps etc.) whereby the removed targets can be taken fromthe end effector then moved to a more suitable destination (e.g. astorage basket, tub, bin, incinerator, composter, or on the ground).Preferably the system is able to target weeds in a way that does notpromote further weed growth by minimising weed seed dispersion.

In some embodiments, the biomass of the targeted weeds to be disposed ofcan be used as an energy source to provide power to the system. This canbe achieved by either an on-board or off-board means for convertingbiomass into electricity, such as direct combustion, pyrolysis,gasification or anaerobic digestion.

In one embodiment the system incorporates various sensors to measurecharacteristics of the target. For example, scales and strain gauges canbe used to measure weight, imaging sensors can measure colour,temperature sensors can measure the temperature, ranging and distancesensors can measure size etc. The information from these sensors may beused for data collection purposes, or more actively as part of a highlevel methodology where only targets meeting a certain criteria aretargeted by the system (e.g. the system is commanded to only weednon-crop vegetation larger than 2 cm diameter). This could be used forselective weeding by being connected to a separate or integratedcomputer system that identifies which weeds should be targeted using thevarious sensors, and controls the end effector and manipulation devicesto weed the targets. The operator can interact with the system at a highlevel to input high level commands, then the computer system can operateindependently with high speed, complex computation and high precisionand accuracy and then report back only the details of importance to theoperator. In more advanced embodiments, the system can automaticallydetect and distinguish between types of weeds and take variouscorrective actions for each one. For example, all weeds of type A can bemechanically weeded, but all weeds of type B should not be mechanicallyweeded due to some adverse effects such as spreading seedlings. In thiscase, the system can automatically log and report on the success rate ofthe automatic mechanical weeding system as well as any outstanding weedswhich may need require alternative methods such as hand removal, flamingor herbicide.

In one embodiment, sensors (e.g. visual, laser, ultrasound, switches)are installed as part of the end effector to determine the state of thetarget (e.g. weed) throughout the manipulation procedure. The system mayincorporate optical flow sensors on the end effector in order to assistthe manipulator to weed the target. This may be particularly useful whenthe platform or tine manipulator incorporates a level of dynamicbehaviour which limits the positioning accuracy of the tine tip.

In certain preferred embodiments, the various sensors and controlalgorithms can advantageously provide relatively high speed and low costspatial manipulation of the system and its end effector.

For mechanical weeding tasks, it is important in some embodiments thatthe system does not misclassify a non-target for a target. It preferablydoes this with near perfect accuracy (i.e. ˜99.9%). This is important inorder to avoid a crop that diminishes to low yields with manydestructive passes. The following equation can be used to determine theapproximate magnitude of potential losses caused by errors in theclassification system:

$\frac{cropDestroyed}{cropInitial} = {1 - ( ( {1 - {P({cropDetectedAsWeed})}} )^{n_{passes}} )}$

For example, a system that incorrectly classifies 1% of the crop as weedwill incorrectly destroy ˜18% of the initial crop after 20 passes. Ifthe system detects a weed as a crop, this is likely less severe thandetecting a crop as a weed, because of the guaranteed loss of yield.

In some embodiments, the system is able to classify targets by inferenceusing measurements of other sets. For example, assuming our system isable to detect vegetation using NDVI and from all vegetation we canclassify what is a crop based on shape, colour, texture or priorpositioning information. Then, the system is able to determine what is aweed because, what is vegetation and not crop is weed, or as a logicalrepresentation:vegetation∧(¬crop)=weed

Furthermore, if the system can identify any two of vegetation, crop orweed with high accuracy, then it can infer the third with high accuracy.

In some embodiments, the system uses machine learning algorithms todetermine what is a target and what is not a target. In otherembodiments, known information can be used to improve the accuracy ofthe classification algorithms. Such an example is the structure of thecrop pattern, which can be modelled based on the method of operation ofthe planting machine. Furthermore, the crop planting centre locationscan be recorded at or shortly after the time of planting to also furtherimprove the classifier accuracy.

In some embodiments, more than one seismograph weeder tine module areoperating in concert. The system is able to coordinate the actuators toachieve the overall objective without the tines colliding into oneanother. In some embodiments, it is preferable to have enoughseismograph tine modules such that in no case does a tine need to belifted up and over a crop or other obstacle (e.g. drip line) in order toreach a target on the other side of the crop. In this situation, thenumber of tines required per bed is preferably one greater than thenumber of obstacle rows (e.g. 1+2 rows of lettuce+1 drip line=4 tinesrequired).

In some embodiments the system includes static guards which prevent thetine from inadvertently striking an area that it should not, for examplethere may be safety guards to constrain the range of motion to a safearea to avoid the tines hitting the surrounding vehicle or users etc.Similarly, an irrigation drip line or the crop itself can be shieldedfrom the tines by using guards protruding down into or slightly abovethe ground. In these embodiments, sensors may also be fitted to detectwhen a limit event has occurred (e.g. by using limit switches).Preferably moving parts of the machine are housed within a protectiveenclosure to minimise the risk of injury to persons nearby.

Preferably, a gearbox is used in combination with an electric motor inorder to control the tine in order to increase the torque from themotor. Such gearboxes can include spur, planetary bevel, harmonic etc.Other means for increasing the force or torque from the actuator includethe use of belts, pulleys, levers, hydraulic pistons and the like.

In one embodiment, a series of seismograph tines have independentactuators for operation in a plane parallel to the ground, and coupledactuators for operation in a plane perpendicular to the ground. Thisallows just a single actuator to lift or lower all seismograph tinesfrom or to the ground, while each tine still has independent horizontalcontrol.

Preferably the module allows for quick and easy swapping or replacementof the tines or end effector so the system can be configured by the userfor a given application. In some embodiments, the end effector of thetine has an attachment or tip end which is selectively interchangeableso that various tip ends can be installed onto the tine, as required forvarious targets and environmental conditions.

For example, the end effector may be a multi-pronged weeding tool 40. Insome embodiments, the multi-pronged weeding tool may be adapted suchthat the prongs can move, independently or jointly, between an openposition and a closed grasping position, thereby to increase theefficiency and practicality of the mechanism. In some forms, the endeffector may incorporate one or more actuators and sensors to controlthe various functions of the tool/prongs. In such embodiments, the endeffector tool could be adapted to be pushed into the ground with theprongs in the open position, the prongs could then be closed to grab anduproot the weed by movement of the end effector in an upward directionaway from the ground. In some embodiments, the multi-pronged weedingtool may be incorporated as part of a rotatable head.

In some embodiments, the end effector may include a releasable lockingmeans having a plunger for energising a biasing element (e.g. spring) soas to positively hold the prongs in the closed position. To dispose ofthe weed, the locking means can be released by way of a latchingmechanism (e.g. electromagnet, electromechanical latch etc.) selectivelyoperable to act against the action of the spring and plunger. The energyof the spring, via the plunger, may cause the prongs to spring opentowards the open position upon release of the locking means, thereby tothrow or shoot the removed weed in a desired direction. In someembodiments, a bin or wheel trough is provided as the direct disposaldestination for the removed weeds, whereby the end effector can drop orthrow the weeds into the bin or wheel trough. Preferably, the binincorporates one or more sensors (e.g. level, mass, etc.) for measuringan amount or level of the contents within the bin. In some embodiments,the bin has a discharge means for emptying the contents of the bin (e.g.manually or when the bin reaches a predetermined state (e.g. full) asdetermined by the sensors). In some embodiments, the discharge means mayinclude an electromechanically operable door that can be selectivelyopened and closed by the control system, thereby to discharge the wasteat a predefined waste disposal area. In other embodiments, the bin maybe fitted with an actuator configured to angle or tip the bin in asimilar control mode, thereby to facilitate discharging of the contentsof the bin.

In other embodiments, the end effector may include a vacuum hose and/ornozzle 45 at or near the end of the tool, which leads to a bin, tank,receptacle or other area (e.g. wheel trough) as the disposaldestination. The vacuum pressure and flow rate is preferably adjustable(manually or automatically) so that it will draw or suck up and removethe selected target, without substantially disturbing non-targets (e.g.weeds but not soil). To aid the removal procedure of rooted weeds, amechanical removal tool end effector can be used in conjunction with avacuum end effector so that once the weeds are uprooted, or loosened andclose to uprooted by the mechanical tool, they are sucked away by thevacuum system.

In some embodiments, sensors (e.g. pressure, vision, mass etc.) areincorporated into the vacuum nozzle, hose or disposal bin to sense thesuccess rate of targets vs. non targets (e.g. weeds vs. soil or otherobjects) being sucked up by the vacuum. The system is then able toautomatically optimise the control and operating parameters of thevacuum (e.g. pressure, flow rate, nozzle diameter, mechanical depths foruprooting etc.) as part of a closed loop vacuum weeding system. In someembodiments, the vacuum is selectively enabled/disabled on demand inorder to optimise energy consumption. In some embodiments, the vacuumsystem incorporates one or more passive filters (e.g. screens, gratings)or active filters (e.g. optical sorting systems) for separating targetsfrom non-targets, or to direct different classes of targets to differentdestinations (e.g. first bin, second bin, etc). In further embodiments,the end effector tool may incorporate a mulching or shredding system,which automatically uproots and shreds/mulches the weeds for furtherdisposal into the vacuum or other disposal unit (e.g. bin). In these andother modes, it is envisaged that the tine makes downward contact withthe ground only when interacting with each target, and otherwise isstowed up above the ground waiting for the next target. Furthermore, thecontrol of the vehicle carrying the weeding system can be coordinatedwith the planning of the weeding tool, as it may be preferable in someinstances to stop the vehicle whilst performing each weeding operation,then control the motion of the vehicle towards the next target in astart/stop driving methodology of the vehicle to each target.

In some embodiments, the vacuum system may include one or more sensors(e.g. flow rate, pressure, current, power, acoustic etc.) fordetermining if there is a complete or partial blockage in the vacuumlines. In such embodiments, the system can positively respond to theblockage with one or more predetermined actions in an effort to removethe blockage. For example, the system may run the vacuum system inreverse (i.e. pumping air out rather than sucking air in), scraping thevacuum end effector on the ground, and/or generating a signal foralerting an operator that a blockage needs to be cleared.

In some embodiments, the tine itself is comprised of a relatively rigidhollow tube member which also acts as a vacuum tube. In otherembodiments, the vacuum tube may be flexible or rigid and integrated asa secondary attachment to the main tine.

In some embodiments, the prongs for the end effector are designed forrelative one way motion of the weeds or targets through the prongs; forexample, using one way hooked teeth or oscillating spears/prongs thatgrab the weed but do not eject, continuously pushing new weeds up to apredetermined end position of the end effector, where a means fordisposal of the weeds is located (e.g. vacuum tube or bin etc.).

In some embodiments, the profile of the tine is designed in a way suchthat it dampens the shock and vibrations. In certain embodiments, aspring and dampener mechanism can be installed in series, or parallelto, the tine mechanism, thereby to provide the desired dampingcharacteristics.

It is envisaged that the weeding mechanisms will primarily be pulled bythe prime mover such that the tines only move in one predetermineddirection. In some embodiments, the tines incorporate a protectiondevice or the system incorporates sensors to detect or prevent damage tothe system if the prime mover attempts to push the mechanisms in theincorrect direction. For example, the system may be fitted with a motionsensor that can detect, for example, if the vehicle is travellingbackwards, whereby the control system provides a signal to automaticallylift all tines off the ground.

In some embodiments, a feature is incorporated for automaticallychanging the tip tool using a tool change mechanism. Preferably, thecomputer control systems can manually or automatically determine thedesired tip tool model, whereby the computer system can accurately planthe tool path according to the specific nature of the tip tool fitted.Various tips can be fitted such as conventional sweeps, or specificallydesigned sweeping cutters for the application.

In some embodiments the tip tool is fitted with either a penetrationdepth sensor or a mechanism designed to passively limit the maximumpenetration depth of the tine. For example, the tip tool can have afixed or adjustable depth stop which allows for horizontal translationof the tip across the ground (e.g. in X- and Y-directions) when inforced contact with the ground, but prevents further movement into theground (e.g. in a Z-direction) due to the large contact area of thedepth stop preventing further penetration.

In some embodiments the tip tool is motorised such that it is capable ofweeding even when the tine is not moving. For example, the tip tool maybe in the form of, for example, a spinning jagged tooth face whichpoints down and makes contact into the ground.

Illustrative examples of high-level control logic and controlmethodologies will now be described with reference to FIGS. 8 to 13. Thedetailed implementation of these methodologies for particularembodiments and applications of the invention will be within theknowledge and expertise of those skilled in the art.

FIG. 8 is a simple flowchart of a high-level control strategy for thesystem, which should be understood in the context of the apparatus andrelated system components previously described. In its most basic form,with some details omitted, the system logic in broad overview is asfollows: —

Overall System Logic

-   -   evaluation of target environment through sensing systems,    -   generation of sensor data based on target environment,    -   activation of automatic target recognition and mechanical        weeding system,    -   killing or dislodging targeted weeds with tine as end effector,    -   re-evaluation of target environment, and    -   generation of new sensor data.

The flowchart of FIG. 9 illustrates in more detail one example of arelatively simple control methodology for locating targets and movingtines between on and off (engaged and disengaged) states, withoutregistration. The methodology for locating targets and engaging tines(using the first control axis), in broad overview, is as follows:

Locating Targets and Engaging Tines (without Registration)

-   -   acquisition of sensor data from the initial target area,    -   segmentation of sensor data from initial target area,    -   classification of segmented data,    -   identification of targets and non-targets in local coordinate        frame based on segmented and classified data,    -   determination of location estimates for targets and non-targets        in local coordinate frame,    -   calculate activation sequence and control tines to turn on and        off for engagement with targets based on location estimates,        depending on which targets are in or out of the manipulation        space, tines in new on or off states.        Controlling Vehicle    -   access world map with localisation and state information,    -   control vehicle to locate and kill new targets.

FIG. 10 shows a more detailed example of a control methodology fortarget acquisition, with registration of targets and non-targets with atarget memory in global coordinates, based on local estimates of targetpositions in a global coordinate frame of reference. This enablesgeneration of a world map including localisation and state informationbased on registered and updated targets in global coordinates. Thismethodology for locating and killing targets with registration, in broadoverview is as follows:

Locating Targets (with Registration)

-   -   acquisition of sensor data from the initial target area,    -   segmentation of sensor data from initial target area,    -   classification of segmented data,    -   identification of targets and non-targets in local coordinate        frame,    -   estimation of location of targets and non-targets in local        coordinate frame,    -   registration of targets and non-targets with memory in global        coordinates based on local to global estimation,    -   updating world map with localisation and state information,        based on registered and updated targets and non-targets in        global coordinates,        Killing Targets    -   accessing world map, with localisation and state information,    -   determination of targets to start and stop killing based on        prioritisation algorithms,    -   calculation and control of tines for engagement and        disengagement with prioritised targets,    -   updating world map with localisation and state information,        Controlling Vehicle    -   accessing updated world map with localisation and state        information,    -   controlling vehicle to locate and kill new targets.

FIG. 11 shows an example of a control methodology for locating targetsand moving tines to a target area. This methodology, in broad overview,is as follows:

Locating Targets and Moving Tines to Target Area (without Registration)

-   -   acquisition of sensor data from initial target area,    -   segmentation of sensor data from initial target area,    -   classification of segmented data,    -   identification of targets and non-targets in local coordinate        frame,    -   determination of location of targets and non-targets in local        coordinate frame,    -   determination of new targets to kill,    -   prioritisation of targets based on prioritisation algorithm,        Killing Targets    -   calculation and control of tines to kill prioritised target        weeds (based on 2-axis control of tines including side to side        trajectory),        Controlling Vehicle    -   accessing world map with localisation and state information,    -   controlling vehicle to locate and kill new targets.

The prioritisation algorithm may be based on a relatively simple“first-in-first-out” (FIFO) prioritisation strategy. In otherembodiments, however, additional optimisation parameters may beincorporated into the control strategy, including vehicle velocity, timeor distance required for the tine to reach each target, error marginsand related consequences (e.g. inadvertently hitting a neighbouringplant rather than a targeted weed in close proximity), opportunity valueparameters (e.g. relative size of different target weeds, proximity oftarget weeds to neighbouring plants, or relative importance of differentweed varieties), and the like. In some embodiments, for example thoseadapted for vacuum weeding, a simple virtual raster scan as defined bythe angular range and velocity of the tine axis in the generallyhorizontal direction and the constant or variable linear motion of thevehicle provides the primary actuator planning path. In this way,targets can be prioritised and acted upon sequentially as they occuralong this polar raster scan. In such embodiments, it will beappreciated that although the vehicle may or may not need to stop ateach target, there is generally no requirement for the vehicle to makeundesirable and inefficient backtracking movement due to the constantlyforward planning methodology.

FIG. 12 shows an example of a control methodology for locating andkilling target weeds, with registration of targets with target memory inglobal coordinates, based on local estimates of target positions in aglobal coordinate frame of reference. Again, this enables generation ofa world map including localisation and state information based onregistered and updated targets in global coordinates.

This methodology for locating and killing target weeds withregistration, in broad overview, is as follows:

Locating Targets (with Registration)

-   -   acquisition of sensor data from initial target area,    -   segmentation of sensor data from initial target area,    -   classification of segmented data,    -   identification of targets and non-targets in local coordinate        frame,    -   determination of location of targets and non-targets in local        coordinate frame,    -   (based on local coordinates derived from segmented and        classified data, and local to global estimation),    -   registration of targets with target memory in global coordinates        based on local to global estimation,    -   updating world map with localisation and state information,        based on registered and updated targets in global coordinates,        Killing Targets    -   accessing world map, with localisation and state information,    -   determination of new targets to kill,    -   prioritisation of targets based on prioritisation algorithm,    -   calculation and control of tines to kill prioritised target        weeds (based on 2-axis control of tines including side to side        trajectory),    -   updating world map with localisation and state information,        Controlling Vehicle    -   accessing updated world map with localisation and state        information,    -   controlling vehicle to locate and kill new targets.

For the embodiment of the invention shown in FIGS. 1 to 4, wherebytargeted weeds are killed, dislodged or disrupted by a side-to-sidetrajectory of the tine in conjunction with forward movement of the UGVor other prime mover, common control functions may be employed,irrespective of the specific targeting and registration strategiesemployed. FIG. 13 shows an example of such common functions for killingtarget weeds based on 2-axis control and side-to-side trajectory of thetine.

This common control methodology, in broad overview, is as follows: —

Killing Targets with Side-To-Side Tine Trajectory

-   -   identification of target weeds to kill in order of priority,    -   calculation of start to finish trajectory including avoidance of        non-targets,    -   calculation of actuator position set points from start to finish        trajectory,    -   controlling actuators to actuator position set points at start,    -   controlling actuators through calculated start to finish        trajectory,    -   updating state information throughout to maintain calculated        trajectory,    -   movement of end-effector (tine) through targets from start to        finish,    -   killing targets based on movement of tine through start to        finish trajectory,    -   updating world map (if relevant), and    -   identification and prioritisation of next targets.

The common control methodology, as defined in FIG. 13, can be adaptedfor tasks where each target requires only manipulation at a predefinedprimary point (e.g. centre point) rather than across a trajectory. Forexample, when vacuum weeding, dripping or using spinning tool endeffectors, the end effector may only need to move to the centre point ofeach target, rather than across a trajectory path through each targetsince the end effector itself is able to effectively kill the entireweed from the centre point of that weed.

In the embodiment of FIGS. 5 to 7, it will be appreciated that thecontrol strategy for determining a side to side trajectory for thesingle tine of the first embodiment will not be directly applicable.Rather, in this case, the control strategy will determine the optimumcombination of tines from the array to activate, and the timing of thatactivation, in order to kill or dislodge the targeted weeds. As shown inFIG. 5, this may involve engagement of discrete combinations or clustersof tines, for example clusters of three, four or five adjacent tinessimultaneously, in order to hit the targeted weeds. Of course, multiplesof such clusters may be activated simultaneously.

The implementation of these control strategies under the rules,guidelines, procedures and objectives as outlined will be well withinthe capabilities of those skilled in the art, and so will not bedescribed in more detail. It will be similarly understood that variousadditional, complementary or alternative control strategies andmethodologies may be utilised for particular applications, within thescope of the inventive concepts as described.

For example, in some embodiments, the end effector may take a form otherthan a tine point such as a round bar, hoe, scythe, knife, cultivator,fork, brush, disk or other implement suited to specific purposes. It mayalso incorporate a robotic or passive gripper as end effector, forcollecting and disposing of weeds in bins or receptacles within range ofthe control axes. It may also incorporate cutting tools such as knives,blades or scissor formations, pollination tools such as dusters,brushes, sprayers or powder blowers, precision applicators such asdrippers, brushes, sprayers or gel applicators, sticky surfacesincorporating tape, glue or other adhesive means, or cleaning tools suchas brushes, brooms, mops, sprayers, steamers, rakes or vacuum nozzles.Furthermore, these tools may also be adapted for various auxiliary tasksbeyond weeding and waste removal such as selectively thinning andselectively harvesting crops. In some embodiments, the classificationprocess may be used to differentiate between targets of different size,shape or colour to determine the weed variety and/or the degree of weeddevelopment and this data may in turn be used to refine the targetingand/or prioritisation processes. Moreover, the apparatus may includeancillary equipment such as irrigation tanks and spray nozzles toirrigate crops at the same time as killing weeds, or incorporate weedcollection implements and receptacles to minimise the propensity forweed re-growth.

The invention in its various preferred forms provides a number of uniqueattributes and advantages, including the flexibility to targetindividual weeds at arbitrary locations, allowing the system to operateeffectively in relatively random as distinct from only in highly orderedor structured environments. The ability of the apparatus to cover morethan one planted row with a single tine leads to benefits in terms ofcost, simplicity, size, weight and operational efficiency. The abilityto disengage the tine(s) from the ground when not in active useminimises drag and soil disruption, which in turn minimises energyconsumption, while also allowing adjustability of the contact force onthe ground as well as penetration depth. The apparatus is able toaccurately target weeds in close proximity to obstacles such as crops,sprinklers, irrigation lines or fence posts.

The ability to trace complex trajectories on the ground or targetspecific points on the ground using a precision tine point, as distinctfrom dragging a relatively wide blade or brush, further enhancesprecision targeting while further minimising soil disruption and energyconsumption. The ability to move only the tine as a simple andlightweight end effector, as distinct from a large-scale implement orimplement assembly, potentially reduces the number of system components,power requirements, mass and complexity. The flexibility for precise andprogressive control over the tine as an end effector by means ofproportional electric servo motors or other progressive actuators, asdistinct from more conventional on-off hydraulic control, is alsoadvantageous. The system is also highly adaptable in terms of itsability to enable substitution of a broad range of alternative endeffectors and associated control strategies, and to integrate with avariety of platforms, devices, prime movers, and other vehiclesincluding autonomous vehicles. In these and other respects, theinvention represents a practical and commercially significantimprovement over the prior art.

Although the invention has been described with reference to specificexamples, it will be appreciated by those skilled in the art that theinvention may be embodied in many other forms.

What is claimed is:
 1. An apparatus for controlling weeds, the apparatusincluding: a plurality of tine formations disposed in a generallytransverse linear array, each tine formation being operable in use toremove or disrupt targeted weeds; a tine support assembly adapted tosupport the tine formations for movement of each tine formation about arespective transverse horizontally oriented rotational control axis in agenerally vertical direction, whereby each tine formation in the arrayis independently movable in use between an engaged position wherein therespective tine formation contacts a ground surface for removal ordisruption of targeted weeds and a disengaged position wherein the tineformation is substantially retracted from the ground surface; aplurality of first actuation mechanisms, each adapted to effect movementof a respective one of the tine formations about it rotational controlaxis; a sensing system for sensing aspects of an environment andgenerating data indicative thereof; a classification system foridentifying target weeds within the environment on the basis of the datafrom the sensing system; and a control system adapted independently toactivate the actuation mechanisms in accordance with a predeterminedcontrol logic thereby to position the respective tine formations fordisruptive contact with the targeted weeds.
 2. The apparatus accordingto claim 1, wherein the rotational control axes of the plurality of tineformations are collinear.
 3. The apparatus according to claim 1, whereinthe rotational control axes of the plurality of tine formations areoffset or staggered.
 4. The apparatus according to claim 1, wherein thetine support assembly comprises a plurality of supporting bodies, andwherein each tine formation is mounted on a respective supporting body.5. The apparatus according to claim 4, wherein the actuation mechanismfor a tine formation is mounted externally to the supporting body. 6.The apparatus according to claim 4, wherein the actuation mechanism fora tine formation is mounted within the supporting body.
 7. The apparatusaccording to claim 1, wherein the actuation mechanism for a tineformation comprises a hydraulic actuator, a pneumatic actuator, and/oran electric servomotor.
 8. The apparatus according to claim 1,comprising a tine self-cleaning control mode wherein the tines cleanthemselves by way of relative movement or rapid shuffling betweenadjacent tines to dislodge earth, rocks or other debris.